In a typical papermaking process, a water slurry, or suspension, of cellulosic fibers (known as the paper “stock”) is fed onto the top of the upper run of an endless belt of woven wire and/or synthetic material that travels between two or more rolls. The belt, often referred to as a “forming fabric,” provides a papermaking surface on the upper surface of its upper run which operates as a filter to separate the cellulosic fibers of the paper stock from the aqueous medium, thereby forming a wet paper web. The aqueous medium drains through mesh openings of the forming fabric, known as drainage holes, by gravity or vacuum located on the lower surface of the upper run (i.e., the “machine side”) of the fabric. 
After leaving the forming section, the paper web is transferred to a press section of the paper machine, where it is passed through the nips of one or more presses (often roller presses) covered with another fabric, typically referred to as a “press felt.” Pressure from the presses removes additional moisture from the web; the moisture removal is often enhanced by the presence of a “batt” layer of the press felt. The paper is then transferred to a dryer section for further moisture removal. After drying, the paper is ready for secondary processing and packaging. 
Cylindrical rolls are typically utilized in different sections of a papermaking machine. Such rolls reside and operate in demanding environments in which they can be exposed to high dynamic loads and temperatures and aggressive or corrosive chemical agents. As an example, in a typical paper mill, rolls are used not only for transporting the fibrous web sheet  between processing stations, but also, in the case of press section and calender rolls, for processing the web sheet itself into paper. 
Typically rolls used in papermaking are constructed with the location within the papermaking machine in mind, as rolls residing in different positions within the papermaking machines are required to perform different functions. Because papermaking rolls can have many different performance demands, and because replacing an entire metallic roll can be quite expensive, many papermaking rolls include a polymeric cover that surrounds the circumferential surface of a typically metallic core. By varying the material employed in the cover, the cover designer can provide the roll with different performance characteristics as the papermaking application demands. Also, repairing, regrinding or replacing a cover over a metallic roll can be considerably less expensive than the replacement of an entire metallic roll. Exemplary polymeric materials for covers include natural rubber, synthetic rubbers such as neoprene, styrene-butadiene (SBR), nitrile rubber, chlorosulfonated polyethylene (“CSPE”—also known under the trade name HYPALON® from DuPont), EDPM (the name given to an ethylene-propylene terpolymer formed of ethylene-propylene diene monomer), polyurethane, thermoset composites, and thermoplastic composites. 
In many instances, the roll cover will include at least two distinct layers: a base layer that overlies the core and provides a bond thereto; and a topstock layer that overlies and bonds to the base layer and serves the outer surface of the roll (some rolls will also include an intermediate “tie-in” layer sandwiched by the base and top stock layers). The layers for these materials are typically selected to provide the cover with a prescribed set of physical properties for operation. These can include the requisite strength, elastic modulus, and resistance to elevated temperature, water and harsh chemicals to withstand the papermaking environment. In addition, covers are typically designed to have a predetermined surface hardness that is appropriate for the process they are to perform, and they typically require that the paper sheet “release” from the cover without damage to the paper sheet. Also, in order to be economical, the cover should be abrasion- and wear-resistant. 
Many covers are formed in a rotational casting operation. In a typical rotational casting process (exemplified in FIGS. 1 and 2), a metallic core 10 is positioned horizontally in a rotating fixture that supports the core 10 at one or both ends. A casting nozzle 12 is  mounted, either directly to the rotating fixture or separately (for example, on a moving cart or carriage), so that it can move along the longitudinal axis of the roll. 
As the casting process commences, the nozzle 12 is positioned above one end of the core 10. The nozzle 12 is continuously supplied with molten polymer 14. As the fixture rotates the core 10 about its longitudinal axis, the nozzle 12 applies a strip 16 of polymeric material to the core 10. As the core 10 rotates, the nozzle 12 translates slowly along the longitudinal axis of the core 10. Typically, the rotational speed of the core 10 and the translation rate of the nozzle 12 are such that, as the core 10 rotates past a specific circumferential location, the nozzle 12 has moved longitudinally a distance that is less than the width of the polymeric strip 16 it is applying. Consequently, each portion of a strip 16 being applied overlies portions of the strips 16a that are applied immediately preceding its application and underlies portions of strips 16b that are applied immediately after its application (see FIG. 2). Because the strips 16 are still molten as they contact each other, bonding can occur between the strips 16 to improve the integrity of the cover. Typically, a portion of a strip 16 will partially overlie portions of between two and seven other strips depending on the material being applied and its thickness. The afore-described process is equally applicable for all layers of a cover (i.e., for the tie-in or top stock layers, the “core” described above comprises the metallic core of the roll and the base and/or tie-in layers that surround it). 
Although the process described above may be adequate for the formation of many covers, it does have at least one potential shortcoming for thick covers, or for thick layers of covers. The polymeric material applied to the core is molten, and is, therefore, somewhat malleable under load (even just the weight of subsequent overlapping layers of polymeric material) until it cures and hardens. The rate of curing for a strip of polymeric material is typically highly dependent on the thickness of the material. As such, when a relatively thick strip of polymeric material is applied to a core, its weight can cause the polymeric strips that were just applied (i.e., those that it partially overlies) to sag under the load. This tendency is exacerbated by the thickness of the underlying polymeric material, which can cause the underlying material to harden more slowly than a thinner strip would. As a result, there tends to be a practical thickness limit for the casting of some materials. 
One approach to forming thicker covers is to maintain a viable thickness in the strips but to increase the extent of the overlap between adjacent layers. In this manner, the  underlying layers can harden quickly, but the ultimate thickness of the entire cover or layer is greater. However, this approach results in a substantial increase in casting time. 
The foregoing demonstrates that different approaches to the formation of covers for industrial rolls are still needed. 